What is perpetual motion?

Question

can it be displayed anywhere in the known universe... eg. the universe is expanding perpetually?

Answer 1

Perpetual means forever...thus it is akin to infinity...you see everything actually is moving (motion) always has and always will...so perpetual motion is the base state!

This being the case it is not unusual to see planets, electrons, etc...always moving...what would be  highly unusual is to find something that is not moving all the time!

So in the end perpetual motion is as irrelevant as infinity.  As both always exist and always will exist and are the base state.

Electrical, magnetic, gravity, nuclear are all simply artifacts of this continual motion...you take away this motion and these energies/fields would go away as well.  Thus these energies are inexhaustible and there for the taking.  You just have to design the proper "paddle wheel".

Answer 2

Perpetual is a relative term. But I cannot think of anything more perpetual than the motions of the universe, such as planets revolving around their suns, suns revolving around the center of galaxies, galaxies expanding outward. They are always in motion.

Answer 3

Perpetual motion is always limited by reactive forces such as friction/time and is thus a theoretical perfection that is not attainable within the universe.

Answer 4

The common definition of perpetual motion, as relating to machines, is something that produces more energy than it comsumes.

The most basic, something that moves without consuming energy, well, if Newton had it right, then the laws of motion ought to give you a big hint on where to look.

A body at rest remains at rest until acted upon by an outside force.

A body in motion, remains in motion, until acted upon by an outside force.

sounds pretty perpetual to me!

What are the forces that might be involved here? and are they truly perpetual, or do they just seem like it from our short life span perspectives?

k